Validation of a Novel Beta Diversion Design Factor for Enhancing Stimulation Efficiency Through Field Cases and Near Wellbore Diversion Model

Abstract

The design of fracture diversion in tight carbonates has been a challenging problem. Recently, a conceptual and theoretical workflow was presented using a β diversion design parameter that uses system volumetric calculations based on high-fidelity modeling and mathematical approximations of the etched system. A robust field validation of that approach and near-wellbore diversion modeling was conducted to extend the application. Extensive laboratory and yard-scale testing data were utilized to realize the diversion processes. Fracture and perforation modeling coupled with fracture diagnostics was used to define system volumetrics, defined as the volume where the fluid needs to be diverted away from. Multimodal particulate pills were used based on a careful review of the size distribution and physical properties. Bottomhole reactions and post-fracturing production for multiple wells and 100 particulate pills were studied to see the effect of the β factor on diversion and production performance. A multiphysics near-wellbore diversion model was used for the first time to simulate the pill effect. Representative wells were selected for the validation study; these included vertical and horizontal wells and varying perforation cluster design, stages, and acid treatments. A complex problem was solved with reaction modeling coupled with near-wellbore diversion for the first time based on given lithology and pumped volumes to match the treatment and diversion differential pressures. Final active fractures and stimulation efficiency were computed through etched geometry. The results showed a range of etched fracture length from 86 to 109 ft and width of 0.05 to 0.08 in. A similar approach was used for perforation system analysis. Diversion pills from 2 to 15 per well were investigated with a 5- to 12-bbl particulate diversion pill range. Finally, the β factor was calculated for each case based on the diversion material and system volumetric ratio. The parameter was plotted against the average diversion pressure achieved and showed an R2 of 0.87. Based on the comprehensive theoretical, numerical modeling, and field-coupled findings, a β factor of 0.8 to 1.0 is recommended for optimum diversion and production performance. For multiple cases, stimulation efficiency and production performance have been enhanced up to 200%. From the field results, it is evident that the design of near-wellbore diversion needs to be strategic. The unique diversion framework provides the basis for such a well- and reservoir-specific strategy. Proper and scientific use of diversion material and modeling can lead to advances in overall project management by optimizing the cost–efficiency–quality project triangle. Digital advancements with digitized cores, fluid systems, and advanced modeling have significant potential for the engineered development of tight carbonates.